在AWS云上搭建K8S集群

1. 新建EC2
   t2.medium
   操作系统是 CentOS 7.5.1804 (x86_64) - with AWS_CLI_SSM and HVM - ami-0229f1a332c972082
   安全组全开，能上网

2. 系统初始化
   yum install -y vim
   yum install -y git
   yum install -y wget
   setenforce 0
   sed -i 's/enforcing/disabled/' /etc/selinux/config

3. 安装docker
   yum install -y docker
   systemctl enable docker.service
   systemctl start docker.service

4. 配置yum源
   cat > /etc/yum.repos.d/kubernetes.repo << EOF
   [kubernetes]
   name=Kubernetes
   baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
   gpgcheck=1
   gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
   EOF

5. 安装kubeadm、kubelet、kubectl
   yum install -y kubelet-1.13.3
   yum install -y kubeadm-1.13.3
   yum install -y kubectl-1.13.3
   systemctl enable kubelet.service
   systemctl start kubelet.service

6. 初始化master（此步骤只需要在master上执行）
   kubeadm init \
   --apiserver-advertise-address=10.44.41.236 \
   --image-repository registry.aliyuncs.com/google_containers \
   --kubernetes-version v1.13.3 \
   --service-cidr=10.96.0.0/16 \
   --pod-network-cidr=10.244.0.0/16

说明：
--apiserver-advertise-address=10.44.41.236 是master的ip地址，
--service-cidr=10.96.0.0/16 是service的地址段，可自定义
--pod-network-cidr=10.244.0.0/16 是pod的地址段，可自定义**

初始化完成之后，会有如下提示，按照提示操作即可
Your Kubernetes master has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
https://kubernetes.io/docs/concepts/cluster-administration/addons/

You can now join any number of machines by running the following on each node
as root:

kubeadm join 10.44.41.236:6443 --token 7dtiw9.7ytxxxxxx89x7tr --discovery-token-ca-cert-hash sha256:c2a0b41860xxxxxxff8dcb5d3b3a460

task 2 创建pod网络，先下载yml文件，再下载docker镜像，然后把docker镜像tag成与yml文件中一致，最后apply
wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
sudo docker pull akinlau/flannel-v0.11.0:v0.11.0
sudo docker images
sudo docker tag ff281650a721 quay.io/coreos/flannel:v0.11.0-amd64
kubectl apply -f kube-flannel.yml

task 3 执行完命令之后在master上查看节点状态，node节点需要很久才能达到ready状态，因为下载flannel镜像很慢，可以将master上的镜像docker save保存，然后拷贝到node上执行docker load导入
[centos@ip-10-44-41-236 ~]$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
ip-10-44-41-236.cn-north-1.compute.internal Ready master 90m v1.13.3
ip-10-44-41-244.cn-north-1.compute.internal Ready <none> 27m v1.13.3
ip-10-44-41-43.cn-north-1.compute.internal Ready <none> 27m v1.13.3